Oh cool! First get the axe from the wall on 2nd floor and go in the garden to cut the tree trunk, obtain the planks and put them to cross the floor on floor 2nd. In that room you'll get a rope. So, if you got the third note too, go back to the warehouse. There will be a hidden trapdoor (it depends on the winds puzzle, but you can stumble against it by walking tbh) and you can descend to the cellar to retrieve the lamp :)
Let me know how it goes!